Place our bets on who's going to be final villain
With the Master Swordsman getting so much hype he's definitely gonna break out of his prison and get his Shinuchi back. However, Yura also wants to wield the Shinuchi. I can see Yura pulling a Zetsu and either sneaking the SM or waiting until he's weakened enough by others who want to stop him and swooping in and swiping the sword for himself.